Masts are widely used in industry, in the military, and in space. Familiar uses for such masts are to support antenna, sensors, and solar panels. Inherently these are long structures, because they are intended to support objects at a considerable distance from the ground or from a vehicle and require a considerable stiffness.
Devices of suitable length are generally not transportable in their extended (deployed) condition. Accordingly a substantial body of art has been developed which provides for storage of the mast elements in smaller envelopes. Examples are collapsible or foldable structures carried in a cannister or other container while collapsed, and are deployed at the point of usage. Some masts can be retracted after deployment; others cannot. Both types are useful.
One typical type of mast may involve three or more flexible longerons coilable in a container. When deployed, they are linked together to form a rigid structure. Another type of mast has hinged-together rigid rods, and means to hold them in a stable configuration. What these types have in common is a considerable bulk and complexity.
There are many applications in which a one-time non-retractable deployment is suitable. In such a situation the potential advantages of storage of the mast material coiled on a reel become available.
In fact, efforts have been made to utilize coiled metal to set up masts. However, in order to maintain structural integrity they use initially curved strip flattened onto the reel, and a plurality of layers. This adds to the cost and weight of the device. Especially in space and airborne applications this is undesirable.
It is an object of this invention to provide a one-shot deployment of initially flat coiled metal into a cylindrical mast, the mast being suitably rigid, and made of a single piece of metal.